The present disclosure relates to a folding antenna device which can be shared in the reception of radio waves in a plurality of different frequency bands.
It has been discussed that a 700-MHz band and a 900-MHz band are allocated as a frequency band of multimedia broadcasting and are used for communication of a mobile phone or the like. Also, a 200-MHz band, which is a high band of a VHS having been used in old analog television broadcasting, has already been used in multimedia broadcasting.
In the past, as an antenna for receiving both frequency bands of a VHF and a UHF indoors, a so-called rabbit ears antenna, or a combination of a folded section of a folded dipole antenna, and a circular loop antenna and a rod antenna is used. The rod antenna is used as an antenna for receiving the VHF band and the loop antenna is used as an antenna for receiving the UHF band.
Also, as an antenna that has been used in the past, there is an omnidirectional antenna for a mobile communication, which includes a rod antenna and a ground (GND). In order to obtain antenna performance in the antenna of the related art, there is a need for a length of a ½ wavelength through a combination of the rod antenna and the GND section. In particular, in a 200-MHz band that is the high band of the VHF band, a ½ wavelength is greater than or equal to 70 cm, which is inconvenient to carry.
As the prior art related to the technology of the present disclosure, there is a dual band antenna for a mobile phone, capable of receiving radio waves in different frequency bands (for example, a 800-MHz band and a 1.5-GHz band) when the antenna is housed and when the antenna is extended (see Patent Literature 1).